From: Oleg Nesterov <oleg@redhat.com>
To: Babanpreet Singh <bbnpreetsingh@gmail.com>
Cc: Christian Brauner <brauner@kernel.org>,
Pavel Tikhomirov <ptikhomirov@virtuozzo.com>,
Andrew Morton <akpm@linux-foundation.org>,
linux-kernel@vger.kernel.org,
syzbot+c382ee653fd70f5cf1bb@syzkaller.appspotmail.com
Subject: Re: [PATCH] pid: use READ_ONCE() in pid_alive()
Date: Fri, 2 Oct 2026 13:59:06 +0200 [thread overview]
Message-ID: <ar-cijUnCr1L8urs@redhat.com> (raw)
In-Reply-To: <20261002012141.7-1-bbnpreetsingh@gmail.com>
On 10/02, Babanpreet Singh wrote:
>
> --- a/include/linux/pid.h
> +++ b/include/linux/pid.h
> @@ -264,7 +264,7 @@ static inline pid_t task_tgid_nr(struct task_struct *tsk)
> */
> static inline int pid_alive(const struct task_struct *p)
> {
> - return p->thread_pid != NULL;
> + return READ_ONCE(p->thread_pid) != NULL;
> }
>
> static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
> diff --git a/kernel/pid.c b/kernel/pid.c
> index 95b8ccfa82690..adf7216067684 100644
> --- a/kernel/pid.c
> +++ b/kernel/pid.c
> @@ -411,7 +411,7 @@ static void __change_pid(struct pid **pids, struct task_struct *task,
> pid = *pid_ptr;
>
> hlist_del_rcu(&task->pid_links[type]);
> - *pid_ptr = new;
> + WRITE_ONCE(*pid_ptr, new);
Acked-by: Oleg Nesterov <oleg@redhat.com>
next prev parent reply other threads:[~2026-10-02 11:59 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-02 1:21 Babanpreet Singh
2026-10-02 6:33 ` Bradley Morgan
2026-10-02 11:59 ` Oleg Nesterov [this message]
2026-10-03 17:22 ` David Laight
2026-10-04 10:55 ` Oleg Nesterov
2026-10-04 11:11 ` Oleg Nesterov
2026-10-04 11:51 ` David Laight
2026-10-04 13:14 ` Oleg Nesterov
2026-10-04 13:31 ` David Laight
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